近40年来新疆策勒绿洲气候变化特征分析

Analysis of the Climate Change Characteristics of Qira Oasis during Last 40 Years

利用策勒县气象站1961-2000年气温和降水观测资料,以回归分析、趋势线分析、5年滑动平均等方法分析了位于昆仑山北麓的策勒绿洲近40年来气温和降水的年际变化、季节变化及变化特征。分析结果显示:(1)近40年来策勒绿洲年均气温总体呈增加趋势,年均气温线性倾向率为0.27℃/10a。从20世纪60年代,气温在平均值附近波动降低,自70年代以来波动较大,并明显升高,气温波动基本上与我国西北地区气温变化趋势一致。年内气温变化存在季节差异,夏、秋和冬三个季节气温均呈上升趋势,春季的气温呈下降趋势,其中冬、秋两季对全年平均气温增加贡献较大。(2)近40年来策勒绿洲年降水量总体呈减少趋势,年均降水量线性倾向率约为-0.63mm/10a,结果与我国西北地区气候由暖干向暖湿转变的趋势相反。20世纪60年代年降水在多年平均值附近波动,增减不明显,自70至80年代波动较大,先减后增,到90年代低水平波动,变干趋势明显。年内降水量变化有明显的季节差异,除了夏季外,春、秋、冬三个季节降水均呈减少趋势,减少幅度从大到小依次为冬季、秋季和春季。

Using the observed temperature and precipitation data from the Qira Meteorology Station during the period from 1961 to 2000, this paper analyzed the annual and seasonal changes of the metrological factors in Qira Oasis during the last 40years with the methods of regression analysis, trend line analysis and 5-year moving average analysis. Tile results show that, （1） During the last 40 years, the temperature of this oasis had a trend of increasing, and the increasing rate was 0.27℃ ＇10a. From middle of 1960s, temperature in this oasis was undulating around the average value. But from 1970s, it showed a larger undulation and increased significantly and kept the same trend with that of the Northwest China. The change of temperature in a year showed seasonal disparities that it had a tendency of increasing in winter, autumn and spring, and decreasing in summer. Among them the temperature changes in winter and spring had more contribution to the annual average temperature change. （2） During the last 40 years, the precipitation of this oasis had a trend of increasing, and the average increasing rate was -0.63mm/10a. This result kept the same trend with that of the Northwest China. From the middle of 1960s to the end of 1970s, precipitation in this oasis was undulating around the average value and did not make any significant change. But from 1980s, it showed a larger undulation and increased significantly. The change of precipitation in a year showed significant seasonal disparities that, except for winter it had a tendency of increasing in other seasons. Summer had the largest increasing rate, following by spring, autumn. Among them the temperature changes in summer and spring had more contribution to the annual average precipitation change, while it was smaller in autumn.